In the past, hair spray propellents consisted essentially of chlorofluorcarbons which had the enormous advantage of not being flammable but which were presumed to have a harmful effect on the ozone layer.
These chlorofluorocarbon (CFC) propellents, better known as "Freons", have been replaced by hydrocarbons which present fewer risks for the ozone layer, such as propane, n-butane; isobutane or their mixtures.
Nonetheless, these hydrocarbons are currently the subject of very serious criticisms, not only concerning hairsprays but also other cosmetic or domestic products because of their very high flammability.
It has also been proposed to use dimethylether or DME which has the advantage of not being toxic, nor dangerous to the environment and which is partially soluble in water which makes it possible to reduce its flammability.
It has however been noted that aerosol systems for hair sprays containing a mixture of water, alcohol and dimethylether. present certain flammability risks when a high resin content and a satisfactory outflow are desired.
With the aim of avoiding the flammability risks, hairsprays based on dimethylether therefore have only a low resin concentration and a relatively low outflow.